LRO Mission Concept of Operations Summary - PowerPoint PPT Presentation

Loading...

PPT – LRO Mission Concept of Operations Summary PowerPoint presentation | free to download - id: 242282-ZDc1Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

LRO Mission Concept of Operations Summary

Description:

First official draft release June 2005 ... Notional launch day information flow. ... 16 kbps housekeeping/engineering data will be received by the KSC GSE and ... – PowerPoint PPT presentation

Number of Views:37
Avg rating:3.0/5.0
Slides: 82
Provided by: ricks71
Learn more at: http://snebulos.mit.edu
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: LRO Mission Concept of Operations Summary


1
LRO Mission Concept of Operations Summary
  • Version 1.0 (Preliminary)
  • April - 2005

2
Goals for ConOps Package
  • Capture operation concepts for both orbiter and
    ground systems
  • Concepts are documented in the LRO Mission
    Concept of Operations (431-PLAN-000052)
  • Early Draft is expected to be released at the end
    of April 2005
  • First official draft release June 2005
  • Final release prior to Mission CDR
  • Once the ConOps document is released, the package
    will be kept current with each new update to the
    document
  • Define mission phases and possible system states
  • Concepts will identify initial activities for
    each mission phase
  • Develop high level time-lines for each phase
  • Package will also identify additional mission
    activities desired for each phase

3
Notes for Concept of Operations Package
  • For each mission sub-phase, activities will be
    broken into space and ground segment.
  • Ground segment is ground assets that support the
    orbiter after launch
  • Space segment is any items that launched by the
    launch vehicle and GSE required to support those
    items

4
TBD/TBR/Action Items List
No. TBD/TDR/Actions Slide/Phase Expected Close Date
1 Verify GSE configuration, do we need command encryption at the launch site? Launch Lunar Transfer
2 Check with propulsion, verify state of ISO valve prior to launch Launch Lunar Transfer
3 Discuss the need for CatBed heaters for potential de-spin. Are they needed based on thermal analysis? If so, do we activate them prior to liftoff? Launch Lunar Transfer
4 Develop required launch window constraints Launch Ascent
5 Update ascent time, either 45 minutes or 20 minutes Launch Ascent
6 CDH S/W Boot mode, does it exist Launch Ascent
7 For each configuration table, resolve TBRs and add items after design as mature All Phases
8 Update De-spin after trade (thruster vs. Yo-Yo) Separation De-Spin
9 Update time duration for De-Spin, Deployment, and Sun Acq. De-Spin Sun Acq.
10 Update after orbiter spin rate is finalized after Sun Acq. Sun Acq.
11 Update initial acq. procedure levels Deployment and Sun Acq.
12 Update details on commissioning orbit after analysis is complete LOI
13 Capture additional details on instrument observations Routine Ops
14 Capture additional details on possible instrument calibrations Routine Ops
5
TBD/TBR/Action Items List
No. TBD/TDR Slide/Phase Expected Close Date
15 Both CRaTER and LEND indicated a desire to be powered during Lunar Cruise. Need to analysis if this is possible and data can be recovered. Lunar Cruise

















6
LRO Mission Phases Definitions
  • LRO Mission Phases are broken down into six main
    phases covering from pre-launch to end-of-mission
    activities
  • Each main phase may have several sub-phases
  • For each main and sub-phase, a start and end
    points are identified
  • If known, an approximate time from launch is
    provided

7
LRO Mission Phase Definition Table
No. Phase Sub-Phases Description
1.0 Pre-Launch/Launch Readiness 1.1 Space Segment Readiness 1.2 Ground Segment Readiness Includes instrument IT, spacecraft/orbiter IT, space/ground segment testing as well as operations preparation and ground readiness testing leading up to launch.
2.0 Launch Lunar Transfer 2.1 Launch and Ascent 2.2 Separation and De-spin 2.3 Deployment and Sun Acq. 2.4 Lunar Cruise 2.5 Lunar Orbit Insertion Includes all activities operations from launch countdown sequence to Lunar Orbit Insertion (LOI). LOI includes all maneuvers necessary to obtain the temporary parking orbit for Orbiter activation and commissioning. During the cruise phase, initial spacecraft checkout will be performed to support activities for MCC and LOI.
3.0 Orbiter Activation / Commissioning 3.1 Spacecraft Act. / Commissioning 3.2 Integrated Instrument Act. / Commissioning Configure and checkout the spacecraft subsystems and ground systems prior to instrument turn-on. Instrument integrated activation will be developed to complete instruments turn-on and commissioning. Instrument commissioning includes any calibration activities needed in the temporary orbit.
4.0 Science Operations 4.1 Measurements (Routine Ops) 4.2 Station-keeping 4.3 Lunar Eclipse 4.4 Yaw Maneuver 4.5 Safehold One year of nominal science collection in the 50 (/- 20) km orbit.
5.0 Extended Mission Operations After 1-year of science observations, orbiter will be boasted into a higher orbit to reduce maintenance requirements. Main purpose for extended mission operations is to perform relay comm. operations. Additional science operations may be performed.
6.0 End-of-Mission Disposal Includes planning and execution of end-of-life operations. Could include controlled/uncontrolled impact on the Lunar surface.
8
LRO Mission Phases Start/End Points
No. Phase Sub-Phases Start Point End Point
1.0 Pre-Launch/Launch Readiness Start of the launch vehicle countdown sequence at KSC. (L-24 hrs)
2.0 Launch and Lunar Transfer 2.1 Launch and Ascent Start of the launch vehicle countdown sequence at KSC, approximately L-24 hrs. Start of payload separation from the launch vehicle third stage. Spacecraft detects separation signal from the launch vehicle, approximately L30 minutes (Short Coast) or L45 minutes (Long Coast)
2.0 Launch and Lunar Transfer 2.2 Orbiter Separation and De-Spin Orbiter detection of payload separation from rocket third stage. Orbiter has de-spin to desired body rates, approximately Separation 10 minutes
2.0 Launch and Lunar Transfer 2.3 Deployment and Sun Acquisition Orbiter body rates are at De-Spin exit criteria. Orbiter solar array is deployed and acquired the Sun (Power Positive), approximately Separation 25 minutes.
2.0 Launch and Lunar Transfer 2.4 Lunar Cruise Orbiter has acquired the Sun and is power positive. Start of the first Lunar Orbit Insertion burn, approximately L4 days
2.0 Launch and Lunar Transfer 2.5 Lunar Orbit Insertion (LOI) Start of first LOI burn Insertion into the spacecraft/instrument commissioning orbit, approximately L7 days
3.0 Orbiter Activation and Commissioning 3.1 Spacecraft activation and commissioning Insertion into the activation/commissioning orbit. Completed spacecraft activation/commissioning. Bus can provide full instrument resources, approximately L21 days
3.0 Orbiter Activation and Commissioning 3.2 Instruments activation and commissioning Completion of spacecraft activation/commissioning. Instrument activated and operating in normal data collection mode. Orbiter is in final mission orbit, approximately L42 days
9
LRO Mission Phases Start/End Points
No. Phase Sub-Phases Start Point End Point
4.0 Routine Operations 4.1 Measurement Operations End of instrument commissioning, instrument calibrations are completed for initial checkout, approximately L 42 days. Approximately 1 year after start of routine measurement operations, approximately L407 days.
4.0 Routine Operations 4.2 Orbit Maintenance and Calibrations Performed monthly Requires 1 day for all activities, actual end point will vary on number of activities
4.0 Routine Operations 4.3 Lunar Eclipse Start configuring the orbiter for Lunar Eclipse End of Lunar Eclipse and return orbiter to nominal configuration.
4.0 Routine Operations 4.4 Yaw Maneuver Start of maneuver for 180 degree Yaw Maneuver Completion of maneuver and return the orbiter to nominal operating mode
4.0 Routine Operations 4.5 Safehold Following safing action that results placing the orbiter into safehold After initial problem is resolved and the ground re-configures the orbiter for nominal operations
5.0 Extended Mission Operations Approximately 1-year after start of nominal measurement operations Completion of extended mission objectives or disposal resource allocations are reached
6.0 End-of-Mission End of extended mission operations or disposal resource allocations are reached. Completion of all end-of-mission disposal activities and mission closeout activities.
10
1.0 Pre-Launch/Launch Readiness
Pre-Launch/Launch Readiness Phase includes
activities during orbiter integration and test
(IT) and ground system IT. The start point of
this phase correspond to the start of orbiter IT
and ground system IT. The phase continues until
the start of the launch vehicle countdown
sequence (Approximately L-24 to 18 hours). This
phase includes two sub-phases, Space Segment
Readiness and Ground Segment Readiness. Space
Segment Readiness sub-phase includes all orbiter
activities associated with preparing the orbiter
for launch. This includes necessary ground
support equipment to support the
activities. Ground Segment Readiness sub-phase
includes all ground system activities associated
with preparing the LRO ground system for launch
and normal operations.
11
1.1 Space Segment Launch Readiness
  • Space Segment Readiness Definition
  • Ground Support Equipment (GSE) development
    testing
  • Integration of spacecraft and instruments
  • Safe-to-mate, interface checks, functional checks
  • Orbiter level functional and performance tests
  • Orbiter level environmental testing
  • Vibration, Acoustics, Thermal Vac/Balance,
    EMI/EMC
  • Orientation for thermal vacuum testing shall be
    the X and Y axis forming the horizontal plane
    /-0.1 inch/2 meters in length
  • All faces of the orbiter shall have clear fields
    of view to cryopanel and/or heater plate and/or
    cal rod arrays
  • Support ground system and operations testing
  • Ship to launch site
  • Launch site processing
  • Post-ship functional/checkout
  • Propulsion system fueling and balance
  • Safe-to-mate with launch vehicle
  • Launch vehicle interface tests and rehearsals
  • Launch site interface tests with ground segment
  • Launch vehicle payload section integration to
    launch vehicle
  • Fairing close-outs

12
1.2 Ground Segment Launch Readiness
  • Ground Segment Launch Readiness Definition
  • Ground software development/releases
  • Three separate software releases
  • Ground system integration and test
  • Ground system verification testing
  • Mission readiness testing (MRT), verify level 3
    requirements
  • Minimum of 5 MRT tests
  • Operations Development
  • Flight Operations plan
  • Flight Procedures
  • Mission Time-lines
  • Mission telemetry command databases
  • Operations training
  • Operations Testing
  • Mission Rehearsals (cover all phases of the
    mission)
  • Mission simulations using either orbiter or high
    fidelity simulator
  • Operations products testing and verification
  • Operations readiness testing (ground system
    proficiency testing)

13
2.0 Launch and Lunar Transfer
The launch and Lunar Transfer phase starts when
the launch vehicle countdown sequence is
initiated at KSC. The launch countdown sequence
typically starts between L-24 hrs and L-18 hrs.
The final activity in this phase is the series of
Lunar Orbit Insertion (LOI) burns to capture into
the commissioning orbit. Sub-Phases are 2.1
Launch and Ascent 2.2 Separation (from launch
vehicle third stage) 2.3 Deployment and Sun
Acquisition 2.4 Lunar Cruise 2.5 Lunar Orbit
Insertion
14
2.0 Launch and Lunar Transfer Timeline
15
2.1 Launch and Ascent
  • Launch and Ascent sub-phase starts at the
    beginning of the launch vehicle countdown
    sequence
  • Pre-plan sequence developed by the launch
    vehicle/KSC team
  • Sequence is used for rehearsals during launch
    readiness phase
  • Launch Window Constraints (TBR)
  • Require sun availability for initial sun
    acquisition (Dont separate and de-spin in
    eclipse)?
  • Possible constraints if LOI is near Beta angle 0
    degrees?
  • Mission Level Activities
  • LRO Project/engineering team will be split, small
    group located at KSC for launch activities.
    Remaining team will be located at the GSFC
    Mission Operations Center (MOC).
  • LRO GSE will be connected to the orbiter through
    hard-line LV interface
  • LRO Launch team will use this interface to power
    and configure the orbiter for launch
  • While the orbiter is powered on the pad, the
    telemetry is relayed back to the MOC at GSFC for
    the remaining project/engineering team.
  • At approximately L-18 hrs, the launch vehicle
    countdown sequence begins
  • Space and ground segment teams configure and
    verify systems prior to launch

16
2.1 Launch and Ascent Sub-Phase
  • Notional launch day information flow. Purpose of
    the information flow is to pass readiness status
    to project representative at the launch control
    room
  • Ground team verifies ground critical elements
  • Launch site team configures and verifies orbiter
    status prior to launch
  • Information is pass through the project
    representative. Polling information is provided
    during the launch vehicle countdown sequence
    activities

17
2.1 Launch and Ascent Sub-Phase
  • Space Segment Concepts
  • KSC project team uses the GSE to power and
    configure the orbiter into the launch
    configuration, reference launch configuration
    table on next slide
  • The GSE located at KSC forwards real-time
    telemetry to the MOC at GSFC
  • Need to add activities on third stage activities
  • CDH Activities
  • Load launch data storage filter table for SBC
    memory recorder
  • DS Filter table will record engineering/housekeepi
    ng data at 16 kbps rate. Expected storage time
    is 1.5 hrs (covers long ascent phase, separation,
    Sun Acq, and small contingency)
  • KSC GSE will use 4 kbps command rate (hard-line)
    to configure orbiter
  • Orbiter will be configured to output 16 kbps
    telemetry during the pre-launch period. 16 kbps
    housekeeping/engineering data will be received by
    the KSC GSE and forwarded to the MOC at GSFC.
  • Verify separation sequence is active
  • Configure S/W mode to Boot (TBR)?
  • Verify launch separation Relative Time Sequences
    (RTSs)

18
2.1 Launch and Ascent Sub-Phase
  • Space Segment Concepts (Continue)
  • Power Activities
  • During orbiter configuration, bring battery
    on-line. Orbiter will switch to internal power
    approximately 30 minutes before liftoff
  • Verify Battery state of charge
  • Verify power configuration is in launch mode
  • Comm. Activities
  • Configure RF switches for omni operations
  • Thermal Activities
  • Configure thermal control system for launch mode
  • Verify deployment heaters are enabled
  • Verify survival heaters are enabled (both for
    spacecraft instruments)
  • Propulsion Activities
  • Verify propulsion configuration for launch mode
  • Question Verify status of isolation valve and
    Catbed operations
  • GNC Activities
  • Verify gyro is powered
  • Verify ACS Software mode
  • Verify remaining GNC components are in launch
    configuration mode
  • GSE

19
2.1 Launch and Ascent Sub-Phase
LRO Orbiter (Space Segment) Launch Configuration (TBR) LRO Orbiter (Space Segment) Launch Configuration (TBR) LRO Orbiter (Space Segment) Launch Configuration (TBR) LRO Orbiter (Space Segment) Launch Configuration (TBR) LRO Orbiter (Space Segment) Launch Configuration (TBR) LRO Orbiter (Space Segment) Launch Configuration (TBR)
Component/System Category Configuration Component/System Category Configuration
CDH Box CDH On LROC Inst. Off
Solid State Recorder CDH Off LOLA Inst. Off
CDH S/W Mode CDH Boot Mode (TBR) LEND Inst. Off
CDH S/W Config CDH Launch DS filter table CRaTER Inst. Off
R-T Telemetry CDH 16 kbps (hardline through LV) LAMP Inst. Off
Cmd Rate CDH 4kbps Diviner Inst. Off
Comm. Cards CDH On Battery Power Online
S-Band Receivers Comm. On PSE Power On
S/Ka Band Xmitter Comm. Off Servo Drive Bus Power Off (TBR)
Transponder Config. Comm. RF Switches configured for Omni Deployment Bus Power Off
Reaction Wheels GNC Off Isolation Valve Prop. Closed (TBR)
Star Trackers GNC Off Prop. Heaters Prop. Enabled
IMU/Gyro GNC On CATBED Heaters Prop. Off (TBR)
ACS S/W Mode GNC De-spin (TBR) Prop. Thrusters Prop. Off
Survival Heater Bus Thermal Enabled Thermal Pumps? Thermal Off
Inst. Survival HTRs Thermal Enabled S/C Ops Heaters Thermal Off
Deployment HTRs Thermal Enabled Inst. Ops Heaters Thermal Off
20
2.1 Launch and Ascent Sub-Phase
  • Ground Segment Concepts
  • Operations team staffs the MOC and flight
    dynamics facilities
  • Ground segment executes the ground system
    countdown sequence
  • Sequence provides a time-line of activities for
    configuring and verifying systems for launch
  • Interface checks with ground network (Cmd/Tlm)
  • Voice comm. configuration/checks
  • Readiness checks for launch critical facilities
    such as the MOC and flight dynamics
  • Readiness information is collected and passed to
    the launch site LRO representative
  • Verify initial acq. data is transferred to the
    ground network
  • Receive orbiter real-time housekeeping data from
    KSC
  • Brief the ground network on initial acq.
    procedures
  • Mission Operations Center is staffed by the
    following teams
  • Flight Operations Team (FOT)
  • Spacecraft engineering team
  • Instrument engineering team
  • Monitor launch vehicle countdown sequence,
    support engineering team at the launch site
  • Configure hardware and software systems for
    initial acquisition

21
2.1 Launch and Ascent Sub-Phase
  • Ground Segment Concept (Continue)
  • Preliminary launch critical ground elements
  • Flight Dynamics Facilities Staffed/Operational
  • Flight Dynamics Analysis Branch
    Staffed/operational
  • Mission Operations Center Staffed/operational
  • Mandatory systems include ITOS, mission planning
    and data archiving systems
  • MOC needs to be staffed by operations team, S/C
    engineers, and instruments engineers
  • Ground Network Operational (initial acquisition
    station)
  • Functions include uplink/telemetry systems,
    tracking systems, data distribution systems
  • Networks Data/Voice networks are operational
    (Between MOC, FDF, FDAB, and ground networks are
    mandatory)

22
2.1 Launch and Ascent
Mission Activity Summary for Launch Ascent Sub-Phase Mission Activity Summary for Launch Ascent Sub-Phase Mission Activity Summary for Launch Ascent Sub-Phase Mission Activity Summary for Launch Ascent Sub-Phase Mission Activity Summary for Launch Ascent Sub-Phase Mission Activity Summary for Launch Ascent Sub-Phase
Activity Affected System Performed By Activity Affected System Performed By
Launch Vehicle Countdown Sequence All LV Team Ground segment launch countdown sequence All Ground Grnd Team
Configure Orbiter to launch mode Orbiter GSE Staff/configure MOC MOC FOT
Monitor orbiter status prior to launch Orbiter LRO Launch Team Staff/Configure FDF/FDAB FD FD Teams
Forward 16 kbps telemetry to MOC GSE GSE Receive 16 kbps from KSC ITOS Launch site GSE
Monitor ground element status All Ground Grnd Team











23
2.2 Separation De-Spin Sub-Phase
  • The separation de-spin sub-phases begins when
    the orbiter detects launch vehicle separation.
    The sub-phase ends when the orbiter is de-spun to
    within the desired rate ranges.
  • Prior to separation, the orbiter remains in the
    launch configuration mode
  • Mission Activities
  • Activities performed by the orbiter is executed
    through the separation sequence. The orbiter
    performs separation activities without ground
    intervention.
  • The separation sequence controls orbiter
    activities through Sun Acquisition

24
2.2 Separation De-Spin Sub-Phase
Separation De-Spin Sequence of Events
25
2.2 Separation De-Spin Sub-Phase
  • Space Segment Concept
  • The launch vehicle will have three separation
    signals that the orbiter monitors
  • Separation is determined when 2 of the 3 signals
    indicate separation
  • Indication of separation will start the
    separation sequence
  • Orbiter does not transmit any telemetry during
    this phase
  • CDH Activities
  • Monitors separation signals, once separation is
    detected, CDH will start the separation sequence
  • Orbiter housekeeping/engineering telemetry
    continues to be stored using the SBC memory
  • GNC Activities
  • Separation sequence verifies/configures the
    orbiter for De-Spin
  • GNC monitors spin rate using the gyro, de-spin is
    complete once orbiter spin rate is reduced to TBR
    rates. Spin rate should be faster than LROC sun
    avoidance requirement. De-spin should take less
    than 10 minutes (TBR) from separation detection.

26
2.2 Separation De-Spin Sub-Phase
LRO Orbiter (Space Segment) Separation De-Spin Configuration (TBR) LRO Orbiter (Space Segment) Separation De-Spin Configuration (TBR) LRO Orbiter (Space Segment) Separation De-Spin Configuration (TBR) LRO Orbiter (Space Segment) Separation De-Spin Configuration (TBR) LRO Orbiter (Space Segment) Separation De-Spin Configuration (TBR) LRO Orbiter (Space Segment) Separation De-Spin Configuration (TBR)
Component/System Category Configuration Component/System Category Configuration
CDH Box CDH On LROC Inst. Off
Solid State Recorder CDH Off LOLA Inst. Off
CDH S/W Mode CDH Boot Mode (TBR) LEND Inst. Off
CDH S/W Config CDH Launch DS filter table CRaTER Inst. Off
R-T Telemetry CDH Off LAMP Inst. Off
Cmd Rate CDH N/A Diviner Inst. Off
Comm. Cards CDH On Battery Power Online (Discharging)
S-Band Receivers Comm. On PSE Power On
S Band Xmitter Comm. Off Servo Drive Bus Power Off (TBR)
Ka Band Xmitter Comm. Off Deployment Bus Power Off
Transponder Config. Comm. RF Switches configured for Omni Isolation Valve Prop. Open
Reaction Wheels GNC Off Prop. Heaters Prop. Enabled
Star Trackers GNC Off CATBED Heaters Prop. Off (TBR)
IMU/Gyro GNC On Prop. Thrusters (TBR) Prop. Off
ACS S/W Mode GNC De-spin Thermal Pumps? Thermal Off
Survival Heater Bus Thermal Enabled S/C Ops Heaters Thermal Off
Inst. Survival HTRs Thermal Enabled Inst. Ops Heaters Thermal Off
Deployment HTRs Thermal Enabled
27
2.2 Separation De-Spin Sub-Phase
  • Ground Segment Concept
  • Ground system elements are in stand-by mode,
    awaiting initial acquisition
  • Following separation, flight dynamics receives
    the separation vector from the launch vehicle
    team
  • Vector is usually faxed to flight dynamics
  • Flight dynamics use the vector to compare launch
    vehicle insertion errors
  • MOC will configure with initial acquisition
    station and perform command/telemetry checks with
    ground site
  • Ground site will use nominal acq. data for
    initial acquisition. Ground site will also have
    initial acq. contingency procedures ready

28
2.2 Separation De-Spin Sub-Phase
Mission Activity Summary for Separation De-Spin Sub-Phase Mission Activity Summary for Separation De-Spin Sub-Phase Mission Activity Summary for Separation De-Spin Sub-Phase Mission Activity Summary for Separation De-Spin Sub-Phase Mission Activity Summary for Separation De-Spin Sub-Phase Mission Activity Summary for Separation De-Spin Sub-Phase
Activity Affected System Performed By Activity Affected System Performed By
Orbiter detects LV separation state Orbiter CDH S/W? Ground Network prepares for Initial Acquisition Grnd Network Grnd
Start separation sequence script Orbiter CDH S/W Verify MOC ITOS systems and engineering system connections Grnd MOC
Store orbiter HK data CDH CDH S/W
Orbiter enters de-spin mode GNC Sep. Seq.
De-spin orbiter to TBR rates GNC ACS S/W
Configure propulsion system for de-spin Propulsion Sep. Seq.












29
2.3 Deployment and Sun Acquisition Sub-Phase
  • Sub-Phase starts after orbiter has de-spun to
    desired rates and ends once the orbiter has
    acquired the sun and is power positive.
  • Mission Activities
  • Solar Array deployment
  • Indexing the solar array position
  • Configuring GNC components for sun acquisition
  • Maneuvering the orbiter to acquire the sun (Power
    Positive)
  • Ground Initial Acquisition
  • Verify orbiter telemetry at the MOC

30
2.3 Deployment and Sun Acquisition Sub-Phase
  • Space Segment Concept
  • Using the separation sequence, the sequence will
    perform the following activities
  • Deploy the solar arrays (perform at least two
    attempts)
  • Index the solar arrays
  • Power the reaction wheels and place the ACS
    software in sun acquisition
  • CDH Activities
  • Continue to execute the separation sequence
  • Collect/store housekeeping data using the SBC
    board memory
  • Power Activities
  • Deploy the solar arrays and command array to
    safehold index
  • Expected time for solar array deployment is 15
    minutes (TBR)
  • GNC Activities
  • After deployment, reaction wheels are powered
  • ACS Software is placed in the sun acquisition
    mode. Using wheels, the orbiter will acquire the
    sun. It is expected that sun acquisition will
    take approximately 20 minutes (TBR).
  • After sun acquisition, the Solar Array (SA)
    boresite will be /- 20 from the sun line
  • Orbiter will spin 0.1/sec (TBR)

31
2.3 Deployment and Sun Acquisition Sub-Phase
  • Space Segment Concept (Continue)
  • Initial Acquisition Procedures
  • Following sun acquisition, the separation
    sequence will configure the orbiter for initial
    acquisition.
  • Separation sequence monitors receiver signal
    strength, if receiver signal strength is greater
    than -95 dBm (TBR), the sequence will command the
    S-Band transmitters on at the 16 kbps rate using
    the omni.
  • After TBD time, the sequence will enter pulse
    mode where is turns the S-Band transmitter on for
    short periods to aid the ground station search
    pattern.

32
2.3 Deployment and Sun Acquisition Sub-Phase
LRO Orbiter (Space Segment) Deployment and Sun Acquisition Configuration (TBR) LRO Orbiter (Space Segment) Deployment and Sun Acquisition Configuration (TBR) LRO Orbiter (Space Segment) Deployment and Sun Acquisition Configuration (TBR) LRO Orbiter (Space Segment) Deployment and Sun Acquisition Configuration (TBR) LRO Orbiter (Space Segment) Deployment and Sun Acquisition Configuration (TBR) LRO Orbiter (Space Segment) Deployment and Sun Acquisition Configuration (TBR)
Component/System Category Configuration Component/System Category Configuration
CDH Box CDH On LROC Inst. Off
Solid State Recorder CDH Off LOLA Inst. Off
CDH S/W Mode CDH Boot Mode (TBR) LEND Inst. Off
CDH S/W Config CDH Launch DS filter table CRaTER Inst. Off
R-T Telemetry CDH 16 kbps LAMP Inst. Off
Cmd Rate CDH 4 kbps Diviner Inst. Off
Comm. Cards CDH On Battery Power Online (Charging)
S-Band Receivers Comm. On PSE Power On
S Band Xmitter Comm. On Servo Drive Bus Power On
Ka Band Xmitter Comm. Off Deployment Bus Power On
Transponder Config. Comm. RF Switches configured for Omni Isolation Valve Prop. Open
Reaction Wheels GNC Off Prop. Heaters Prop. Enabled
Star Trackers GNC Off CATBED Heaters Prop. Off
IMU/Gyro GNC On Prop. Thrusters (TBR) Prop. Off
ACS S/W Mode GNC De-spin Thermal Pumps? Thermal Off
Survival Heater Bus Thermal Enabled S/C Ops Heaters Thermal Off
Inst. Survival HTRs Thermal Enabled Inst. Ops Heaters Thermal Off
Deployment HTRs Thermal Enabled
33
2.3 Deployment and Sun Acquisition Sub-Phase
  • Ground Segment Concept
  • Ground Network
  • Ground site will perform initial acquisition
    based on nominal predicts
  • After TBD time, contingency search patterns will
    be executed
  • Ground site will be configured for 16 kbps
    real-time telemetry and 4 kbps command uplink
  • Initial acquisition procedures will be directed
    by the LRO operations team
  • MOC
  • After initial acquisition, real-time telemetry
    (16 kbps) is received at the MOC.
  • MOC teams will monitor and evaluated orbiter
    health
  • FOT will perform command checks using command
    encryption
  • Orbiter configuration checks are executed using
    ITOS
  • Orbiter real-time 16 kbps data is forwarded to
    KSC GSE for launch site team
  • Flight Dynamics
  • Start processing tracking data from ground
    network
  • Based on errors, re-issue acq and planning
    products

34
2.3 Deployment and Sun Acquisition Sub-Phase
Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase
Activity Affected System Performed By Activity Affected System Performed By
Configure for Solar Array Deployment Power, CDH Separation Sequence Perform initial acquisition Grnd Ground Network
Deploy Solar Array, multiple attempts Power, CDH Separation Sequence Verify 16kbps telemetry rate after initial acq. Grnd MOC
Configure ACS Software for Sun Acquisition mode Power, CDH, GNC Separation Sequence Send test commands Grnd, Orbiter MOC
Acquire Sun Power, GNC ACS S/W Orbiter configuration checks Grnd MOC
Configure spacecraft for initial acquisition with ground System Separation Sequence Forward 16kbps real-time telemetry to KSC Grnd MOC
Power on reaction wheels Power, GNC Separation Sequence Receive LV separation vector from launch vehicle team FD LV Team
Verify power positive condition Orbiter MOC
Change telemetry data rate to 300 kbps Comm, CDH, Grnd MOC
Dump SBC stored engineering data Comm, CDH, Grnd MOC, CDH S/W






35
2.4 Lunar Cruise Sub-Phase
  • Sub-Phase starts after orbiter has deployed the
    solar arrays and acquired the Sun.
  • Orbiter should be power positive and dumping the
    stored engineering data from the SBC memory.
  • Mission Activities
  • Collect Doppler and range data for MCC maneuver
  • Configure GNC and propulsion for MCC maneuver
  • Start initial spacecraft activation sequence
  • Perform ground network checks

36
2.4 Lunar Cruise Sub-Phase
Lunar Cruise Sequence of Events
37
2.4 Lunar Cruise Sub-Phase
  • Space Segment Concepts
  • CDH
  • Commissioning SSR
  • Transitioning software to nominal mode
  • Configuring safing software
  • Verify CFDP processing
  • Power
  • Configuring power parameters
  • Enable servo drive bus and electronics
  • Propulsion
  • Configure propulsion system for maneuvers
  • Perform MCC maneuver
  • Characterize propulsion system prior to LOI
  • GNC
  • Transition ACS to point mode
  • Commission star trackers
  • Characterize ACS performance
  • Comm.
  • Deploy HGA

38
2.4 Lunar Cruise Sub-Phase
LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR)
Component/System Category Configuration Component/System Category Configuration
CDH Box CDH On LROC Inst. Off (Contam. HTRs On?)
Solid State Recorder CDH On LOLA Inst. Off
CDH S/W Mode CDH Normal Mode (TBR) LEND Inst. Off
CDH S/W Config CDH Nominal Config. CRaTER Inst. Off
R-T Telemetry CDH 16 kbps (Nominal) LAMP Inst. Off (Contam. HTRs On?)
Cmd Rate CDH 4 kbps (Nominal) Diviner Inst. Off
Comm. Cards CDH On Battery Power Online (Charging)
S-Band Receivers Comm. On PSE Power On
S Band Xmitter Comm. On Servo Drive Bus Power On
Ka Band Xmitter Comm. Cycle Deployment Bus Power On
Transponder Config. Comm. RF Switches configured for Omni Isolation Valve Prop. Open
Reaction Wheels GNC On Prop. Heaters Prop. Enabled
Star Trackers GNC On CATBED Heaters Prop. Cycle
IMU/Gyro GNC On Prop. Thrusters (TBR) Prop. On
ACS S/W Mode GNC Point Mode Thermal Pumps? Thermal On
Survival Heater Bus Thermal Enabled S/C Ops Heaters Thermal On
Inst. Survival HTRs Thermal Enabled Inst. Ops Heaters Thermal Off
Deployment HTRs Thermal Enabled
39
2.4 Lunar Cruise Sub-Phase
  • Ground Segment Concepts
  • Ground Network
  • Performing CFDP during Ka-band test passes
  • Supporting various cmd uplink rates
  • Supporting various telemetry D/L rates
  • Forwarding stored engineering data to MOC
  • Passes Real-time telemetry to MOC
  • Performing continuous ranging/Doppler tracking
    and forwarding to flight dynamics
  • MOC
  • Receiving and processing real-time and stored
    orbiter data
  • Executing the spacecraft commissioning time-line
  • Spacecraft and instrument engineers monitoring
    orbiter systems at MOC
  • Passes mission planning products to instrument
    SOCs
  • Track fuel usage
  • Perform trending on selected telemetry points
  • MOC is staffed 24 hrs, prime activities occur
    during first shift
  • Flight dynamics
  • Generate mission products
  • Develop MCC plan

40
2.4 Lunar Cruise Sub-Phase
Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase Mission Activity Summary for Deployment and Sun Acquisition Sub-Phase
Activity Affected System Performed By Activity Affected System Performed By
Perform MCC burn Propulsion, GNC MOC, CDH S/W Orbiter tracking Ground Network Ground Network
Deploy HGA Power, Mech, GNC MOC Executing commissioning timeline Orbiter MOC
Power Commissioning Power MOC Orbiter telemetry trending MOC MOC
CDH Commissioning CDH MOC Process tracking data FD, GN FD
Thermal Commissioning Thermal MOC Generate mission products MOC, FD MOC, FD
Propulsion Commissioning Propulsion MOC
Comm. Commissioning Comm. MOC








41
2.5 Lunar Orbit Insertion (LOI) Sub-Phase
  • Sub-phase starts at the beginning of the first
    LOI burn
  • Mission Activities
  • Perform the series of LOI burns to capture into
    the commissioning orbit
  • Commissioning orbit is 90x110 km
  • 90 inclination

42
2.5 Lunar Orbit Insertion (LOI) Sub-Phase
  • Space Segment Concept
  • Propulsion
  • Configure propulsion system for LOI burns
  • Series of 3 burns over approx. 2 days to capture
    into the commissioning orbit
  • Each maneuver involves
  • Configuring prop. System (enable CatBed,
    thrusters, etc)
  • Pointing S/C
  • Transition to delta-V mode
  • Return to 3-Axis point and nominal pointing
  • Comm
  • Since off-point is needed, omni will be used for
    S-Band
  • Assume nominal 16 kbps rate

43
2.5 Lunar Orbit Insertion (LOI) Sub-Phase
LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR) LRO Orbiter (Space Segment) Lunar Cruise Configuration (TBR)
Component/System Category Configuration Component/System Category Configuration
CDH Box CDH On LROC Inst. Off (Contam. HTRs On?)
Solid State Recorder CDH On LOLA Inst. Off
CDH S/W Mode CDH Normal Mode (TBR) LEND Inst. Off
CDH S/W Config CDH Nominal Config. CRaTER Inst. Off
R-T Telemetry CDH 16 kbps (Nominal) LAMP Inst. Off (Contam. HTRs On?)
Cmd Rate CDH 4 kbps (Nominal) Diviner Inst. Off
Comm. Cards CDH On Battery Power Online (Charging)
S-Band Receivers Comm. On PSE Power On
S Band Xmitter Comm. On Servo Drive Bus Power On
Ka Band Xmitter Comm. Cycle Deployment Bus Power Off
Transponder Config. Comm. RF Switches configured for Omni/HGA Isolation Valve Prop. Open
Reaction Wheels GNC On Prop. Heaters Prop. Enabled
Star Trackers GNC On CATBED Heaters Prop. Cycle
IMU/Gyro GNC On Prop. Thrusters (TBR) Prop. On
ACS S/W Mode GNC Point Mode/Delta-V Thermal Pumps? Thermal On
Survival Heater Bus Thermal Enabled S/C Ops Heaters Thermal On
Inst. Survival HTRs Thermal Enabled Inst. Ops Heaters Thermal Off
Deployment HTRs Thermal Enabled
44
2.5 Lunar Orbit Insertion (LOI) Sub-Phase
  • Ground Segment Concept
  • Ground Network
  • Maneuvers may need to be supported by DSN
  • Continuous tracking
  • MOC
  • Upload LOI plans and monitor burns
  • Monitor orbiter systems
  • Track fuel usage
  • 24 hour coverage (Staffed)
  • Flight Dynamics
  • Plan LOI burns
  • Monitor performance
  • Update mission products
  • Process continuous ranging/Doppler data

45
3.0 Orbiter Commissioning
The orbiter activation and commissioning phase
starts once the orbiter reached the commissioning
orbit. The final step in orbiter commissioning is
inserting into the final mission orbit of 50 km.
A portion of the spacecraft activation sequence
is executed during the cruise phase. Sub-Phases
are 3.1 Spacecraft Activation and
commissioning 3.2 Integrated Instrument
activation and commissioning
46
3.0 Orbiter Commissioning
  • Definitions
  • Commissioning includes both activation and
    cal/val
  • During activation, sequence includes powering
    components and functionally verify systems.
  • During Cal/Val, system performance is verified
  • Instrument Cal/Val sequence should be defined by
    the Science Team
  • Instrument teams will develop individual
    Instrument activation sequence and the project
    will develop the integrated activation sequence.
  • Sequence will minimize the overall time

47
3.1 Spacecraft Commissioning
  • Space Spacecraft Commissioning Concept
  • Portion of activities will be performed during
    cruise sub-phase
  • Power
  • Verify power analysis
  • Modify any power parameters
  • GNC
  • Operate in point mode with gyro, ST, wheels and
    KF
  • Monitor SA and HGA operations
  • Maintain Sun Avoidance for instruments
  • Perform ACS calibrations (bias, alignment
    updates)
  • Thermal
  • Configure thermal system
  • Verify heater configurations
  • Propulsion
  • Verify/Update thruster efficiency, alignments
  • Comm
  • Check Ka system
  • Dump data through S-Band (Ka Contingency)
  • S/Ka link analysis

48
3.1 Spacecraft Commissioning
LRO Orbiter (Space Segment) Spacecraft Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Spacecraft Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Spacecraft Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Spacecraft Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Spacecraft Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Spacecraft Commissioning Configuration (TBR)
Component/System Category Configuration Component/System Category Configuration
CDH Box CDH On LROC Inst. Off (Contam. HTRs On)
Solid State Recorder CDH On LOLA Inst. Off
CDH S/W Mode CDH Normal Mode (TBR) LEND Inst. Off
CDH S/W Config CDH Nominal Config. CRaTER Inst. Off
R-T Telemetry CDH 16 kbps (Nominal) LAMP Inst. Off (Contam. HTRs On)
Cmd Rate CDH 4 kbps (Nominal) Diviner Inst. Off
Comm. Cards CDH On Battery Power Online (Cycle)
S-Band Receivers Comm. On PSE Power On
S Band Xmitter Comm. On Servo Drive Bus Power On
Ka Band Xmitter Comm. Cycle Deployment Bus Power Off
Transponder Config. Comm. RF Switches configured for HGA Isolation Valve Prop. Open
Reaction Wheels GNC On Prop. Heaters Prop. Enabled
Star Trackers GNC On CATBED Heaters Prop. Off
IMU/Gyro GNC On Prop. Thrusters (TBR) Prop. On
ACS S/W Mode GNC Point Mode Thermal Pumps? Thermal On
Survival Heater Bus Thermal Enabled S/C Ops Heaters Thermal On
Inst. Survival HTRs Thermal Enabled Inst. Ops Heaters Thermal Off
Deployment HTRs Thermal Enabled
49
3.1 Spacecraft Commissioning
  • Ground Segment Concepts
  • Ground Network
  • Supporting various data rates and modes
  • Generate tracking data
  • MOC
  • Perform commissioning sequence
  • Spacecraft engineers at MOC supporting activities
  • MOC operates on extended operations (12 to 16 hrs
    per day)
  • MOC forwards real-time and stored engineering
    data to the instrument SOCs
  • Flight Dynamics
  • Process tracking data
  • Generate mission products on a weekly basis

50
3.2 Integrated Instrument Commissioning
  • Integrated Instrument Commissioning
  • Instrument Activation Activities
  • Deploying any doors or protective covers
  • Powering electronic components
  • Running functional checks on systems
  • Configuring instruments for Cal/Val activities
  • Spacecraft will collect and stored instrument
    data on SSR
  • Instruments Cal/Val Activities
  • Perform initial Cal/Val activities as defined by
    the science team to validate the instruments
    performance
  • Based on Cal/Val activities, instrument operating
    parameters are adjusted to improve performance
  • Final Mission Orbit Insertion
  • Additional two burns are needed to reach the
    final mission orbit of 50 km
  • Burns sequence are similar to the LOI burns
  • Configuring prop. System (enable CatBed,
    thrusters, etc)
  • Pointing S/C
  • Transition to delta-V mode
  • Return to 3-Axis point and nominal pointing

51
3.2 Integrated Instrument Commissioning
  • Ground Segment Concept
  • Ground Network
  • Follows a typical scenario support
  • At least 30 minutes of S-Band support per orbit,
    more can be added depending on final Cal/Val plan
  • Dump SSR at the one Ka site
  • MOC
  • Executes the Cal/Val activities through ground
    procedures or on-board stored commanding
  • Real-time housekeeping data is forwarded to the
    instrument SOCs
  • MOC is staffed by spacecraft and instruments
    engineering teams
  • Mission products are distributed to all ground
    elements
  • Flight Dynamics
  • Process tracking data
  • Generate mission products
  • Monitor commissioning orbit and plan for
    transition to final mission orbit
  • Instrument SOCs
  • Backup engineering support for instruments
  • Can receive real-time housekeeping telemetry from
    the MOC
  • Receive stored measurement data from the MOC for
    processing
  • Forwards results of data analysis to engineering
    team at the MOC for additional Cal/Val activity
    planning

52
3.2 Integrated Instrument Commissioning
LRO Orbiter (Space Segment) Integrated Instrument Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Integrated Instrument Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Integrated Instrument Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Integrated Instrument Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Integrated Instrument Commissioning Configuration (TBR) LRO Orbiter (Space Segment) Integrated Instrument Commissioning Configuration (TBR)
Component/System Category Configuration Component/System Category Configuration
CDH Box CDH On LROC Inst. On
Solid State Recorder CDH On LOLA Inst. On
CDH S/W Mode CDH Normal Mode (TBR) LEND Inst. On
CDH S/W Config CDH Nominal Config. CRaTER Inst. On
R-T Telemetry CDH 16 kbps (Nominal) LAMP Inst. On
Cmd Rate CDH 4 kbps (Nominal) Diviner Inst. On
Comm. Cards CDH On Battery Power Online (Cycle)
S-Band Receivers Comm. On PSE Power On
S Band Xmitter Comm. On Servo Drive Bus Power On
Ka Band Xmitter Comm. Cycle Deployment Bus Power Off
Transponder Config. Comm. RF Switches configured for HGA Isolation Valve Prop. Open
Reaction Wheels GNC On Prop. Heaters Prop. Enabled
Star Trackers GNC On CATBED Heaters Prop. Off
IMU/Gyro GNC On Prop. Thrusters (TBR) Prop. On
ACS S/W Mode GNC Point Mode Thermal Pumps? Thermal On
Survival Heater Bus Thermal Enabled S/C Ops Heaters Thermal On
Inst. Survival HTRs Thermal Enabled Inst. Ops Heaters Thermal On
Deployment HTRs Thermal Enabled
53
4.0 Measurement Operations
  • Measurement operations is the routine mission
    phase for LRO. The phase starts once LRO enters
    its final mission orbit and all spacecraft and
    instruments commissioning activities are
    complete. Throughout the measurement operations,
    there are five sub-phases
  • Routine Operations
  • Station Keeping/Calibrations
  • Lunar Occultation
  • Yaw Maneuvers
  • Safehold

54
4.1 Routine Operations
  • Orbit View
  • Twice a year, LRO will be in full Sun for roughly
    1 month (Continuous)
  • Max Lunar Occultation is 48 minutes per orbit
  • Twice a year, LRO will perform a yaw maneuver to
    keep the Sun on the correct side of the
    spacecraft
  • Twice a month, LROs orbit will be in full view
    of the Earth for a period of approximately 2 days
  • Once a month, LRO will perform a set of
    station-keeping maneuvers (combined Delta-V
    Delta-H). Maneuvers will interrupt science for 1
    orbit each month (2 hrs)
  • Twice a year (on average) the Earth will pass
    between the Moon and Sun (Lunar Eclipse),
    interrupting science for approximately 3 orbits
    Worse case (6 hrs)

55
4.1 Routine Operations (Daily Measurement
Timeline)
56
4.1 Routine Operations
  • Space Segment Concepts
  • Mission Orbit
  • 50 km (/- 20 km)
  • Approximately 90 lunar equatorial inclination
    drifts about 0.5 /year
  • Orbit period 113 minutes
  • Orbiter Pointing
  • Nadir pointing to control accuracy of 60 arc-sec
    (3s) per axis
  • Pointing stability (3s per axis)
  • 5 arc-sec/axis over 1 ms
  • 10 arc-sec/axis over 100 ms
  • 20 arc-sec/axis over 4 sec
  • Nominal command rates 2 kbps or 4 kbps
  • Nominal real-time telemetry rates 16 kbps or 32
    kbps
  • Spacecraft housekeeping storage rate to the SSR
    is 32 kbps

57
4.1 Routine Operations
  • Space Segment Concepts (Cont.)
  • LROC
  • Takes between 9 and 18 NAC image pairs each orbit
    (primary image collection over the Sun-lit
    portion of the orbit)
  • WAC collects image 1 Mbps over Sun-lit portion
    of the orbit
  • Each NAC image takes 15 seconds to fill the
    camera buffer
  • Camera buffer is transferred to the spacecraft
    SSR in approximately 206 seconds
  • LROC observations include occasional slews
  • Slews up to 20 degrees are planned
  • Spacecraft slews are 20 seconds (allow NAC buffer
    to fill for image). Slew time does not take into
    account maneuver and settling time.
  • LROC requested 3 of the observations include
    slews and that the slews are evenly distributed
    over the year
  • Requires daily command sequence to control the
    WAC and NAC images
  • Command sequence is generated by the LROC SOC and
    transferred to the GSFC MOC for processing
  • LROC images are compressed by LROC 11.7
    compression ratio
  • LROC is powered cycle during the night portion of
    the orbit, power cycle is performed out of the
    stored command load
  • LOLA
  • Instrument is on and collects measurement data
    over the entire orbit at 10 kbps rate
  • Does not require daily command sequences,
    occasional real-time commands may be required to
    adjust instrument parameters
  • LEND
  • Instrument is on and collects measurement data
    over the entire orbit at 0.035 kbps rate

58
4.1 Routine Operations
  • Space Segment Concept (Cont.)
  • LAMP
  • Instrument is collecting measurement data over
    the night portion of the orbit at a rate of 20.2
    kbps
  • LAMPs HV is disable prior to crossing the
    terminator line and enabled shortly after
    crossing the terminator line
  • Baseline concept calls for this sequence to be in
    the daily load based on flight dynamics predicts.
    Due to the uncertainty in the predicts (5
    seconds), alternative solutions may be looked at.
  • LAMP Housekeeping rate is 800 bps
  • CRaTER
  • Instrument is collecting measurement data over
    the entire orbit
  • Two possible data rates 0.2 kbps during
    non-flare conditions, 100 kbps during flare
    conditions
  • Flare conditions could last for a few days
  • Diviner
  • Instrument is collecting measurement data over
    the entire orbit at a rate of 10.6 kbps
  • Instrument performs internal calibration
    throughout the orbit, 12 times per orbit
  • Diviner needs a signal/command from the
    spacecraft when crossing the Moons equator
    (within 2 to 3 seconds).

59
4.1 Routine Operations
Daily Data Calculation assuming 16 NAC pairs and
CRaTER sampling at 100 kbps
60
4.1 Routine Operations (Min. Data Volume Case)
61
4.1 Routine Operations (Max Data Volume Case)
62
4.1 Routine Operations
LRO Ground System Architecture
63
4.1 Routine Operations
  • Ground Segment Concepts (Cont)
  • Ground Network Concept
  • One new 18m aperture Ka/S dual feed ground
    antenna located at White Sands.
  • Combination of 2 to 3 existing NENS/GN/Commercial
    S-band stations to provide remaining S-Band daily
    coverage.
  • Additional sites S-Band sites may be utilized for
    backup/contingency operations.
  • Ground Network Communication Characteristics
  • Ka-Band Downlink (25.5 27 GHz )
  • Support 284 Msymbols downlink rate/1311 Gsymbols
    per day
  • Support CFDP CCSDS file data protocol
  • Support Reed-Solomon convolution encoding schemes
  • Required Station G/T(2) 45 dB/K
  • S-Band Up/Downlink TTC (2104/2287 MHz)
  • 1 mm/s Doppler (2-way)
  • 15 m ranging (2-way)
  • Support command rates of 2, 4,16, 32 kbps (1)
  • Support telemetry rates of 4,16,32, 300 kbps
    (1)
  • Near Continuous S-band coverage required
  • Minimum 30 minutes per orbit during lunar
    near-side passage

64
4.1 Routine Operations Ground Network Support)
65
4.1 Routine Operations Ground Network Ka Dump
Concept
66
4.1 Routine Operations
  • Ground Segment Concept (Cont.)
  • Ground Network Contingency Operations
  • With only 1 Ka-band site for high measurement
    downlink, interruptions to measurement
    observations are increased due to equipment
    failure and routine maintenance
  • Newer antenna will hopefully offset equipment
    failure risk
  • Routine maintenance can be schedule during off
    hours
  • If failure to antenna does occur, a couple of
    scenarios are possible to maintain current or
    modified observations
  • Using the 300kbps S-Band rate, can dump all but
    LROC data for 1 day
  • Need additional coverage to replace White Sands,
    possible sites are Hawaii, and Wallops?
  • Fall back to DSN for S-Band coverage. Using DSN
    we can utilize the 2.5 Mbps S-Band rate. Dump
    all non LROC data plus modified LROC image
    sequence.

67
4.1 Routine Operations
  • Ground Segment Concepts (Cont.)
  • Flight Dynamics
  • Flight Dynamics Facility (FDF)
  • Perform orbit determination and attitude support
About PowerShow.com